Senior Full Stack Java Developer Jobs in Kansas (NOW HIRING)

Position Overview:
We are looking for a highly skilled Senior Android Platform Engineer to play a critical role in the development of Walt OS, the custom operating system powering our future devices. You will drive our Android system modifications, collaborate on technical specifications with our hardware partners, and own the integration of critical hardware domains including custom audio, networking, motion sensors, and power management.

While your primary focus is helping devices and evolving the device OS, you will also leverage your full-stack knowledge to understand, integrate with, and contribute to our broader tech stack, including our Node.js backend services and React Native applications.

Responsibilities

• Develop the Walt OS: Architect, implement, and continuously improve the custom Android 14 or later image for our devices, optimizing heavily for rugged, frontline environments.

• Own Core Hardware Domains: Lead the systems-level engineering for audio routing, network stability, precision location tracking, motion detection, and aggressive power management.

• Vendor Collaboration: Act as a key technical contact with our ODMs, reviewing implementations, troubleshooting integration issues, and ensuring hardware-software harmony.

• Cross-Functional Engineering: Contribute to our scalable backend services (Node.js) and mobile applications (React Native) to ensure seamless, real-time data sync between the device and the wider platform.

• Strategic Execution: Make technical tradeoffs that balance the immediate goal of launching Walt 2 with the long-term architectural health of the platform.

• Mentorship: Provide technical guidance to other engineers on the team regarding systems-level architecture and Android platform best practices.

Required Skills and Qualifications:

• Languages & Systems Engineering: Expert-level proficiency in Kotlin and Java for framework/app-layer integration, paired with strong skills for modifying the Android native services.
• Cross-Stack Capability: 3+ years of experience in at least one other core area of our stack: building RESTful APIs/microservices in Node.js OR developing cross-platform mobile applications using React Native.

• Hardware & Sensor Integration:

  • Audio & Real-Time Communication: Deep knowledge of Android's audio routing framework, enabling ultra-low latency push-to-talk (PTT), noise cancellation, and STT/TTS capabilities.

  • Networking: Experience modifying the networking stack for seamless connectivity handoffs and robust communication in complex, high-interference environments.

  • Location & Motion Services: Proven ability to integrate and optimize GPS, BLE, accelerometers, and gyroscopes for precise real-time tracking, motion detection, and SOS/safety alerting.

  • Power Management: Expertise in OS-level battery optimization, wakelock management, and profiling to ensure devices easily survive a full industrial shift.

Core Competencies

• High Agency: You take ownership of problems and drive them to resolution with minimal supervision. You don't wait for direction—you identify issues, propose solutions, and execute.

• Fast Learner: You quickly grasp new technologies, frameworks, and domain knowledge. You're comfortable diving into unfamiliar territory and becoming productive quickly.

• Tradeoff Intelligence: You make educated decisions between time to market and technical excellence. You understand when to ship fast vs. when to invest in scalability, and you can articulate the rationale behind your choices.

Preferred Skills and Qualifications:

• Experience building distributed backend systems (Node.js) and understanding load balancing, caching, and message queues.
• Knowledge of cloud platforms (Azure preferred) and containerization (Docker, Kubernetes).
• Familiarity with enterprise fleet management and closed-system device lockdown strategies.
• Experience developing hardware-as-a-service products.
• Hardware/ODM Collaboration: Experience working directly with overseas ODMs/OEMs to implement hardware specifications, navigate board support packages (BSPs), and integrate custom firmware.
• Firmware development: Strong C/C++ skills for modifying the Android Hardware Abstraction Layer (HAL), JNI, and native services.
• Android Platform/AOSP: 5+ years of deep experience modifying and building custom Android OS images (AOSP). Proven experience with Android 14 or later is highly preferred.